Wasington, Apr 28 (IANS): US Secretary of Defence James Mattis has said that Washington will discuss with allies and Pyongyang the need to retain American troops on the Korean Peninsula.

The issue is among those Washington will discuss first with its and then with North Korea, Mattis said on Fridaywhile meeting his Polish counterpart Mariusz Blaszczak at the Pentagon.

He added that the US "will build, through confidence-building measures, a degree of trust if it's going to go forward", referring to the dialogue with North Korea on the denuclearisation issue, reports Xinhua news agency.

US President Donald Trump in March threatened to withdraw troops from the Korean Peninsula in an attempt widely seen to pressure Seoul to make concessions in bilateral trade dialogues.

The US troops have remained in South Korea ever since the signing of an armistice treaty at the end of 1950-1953 Korean War.

Bilateral relations have been strained over issues like defence burden sharing, the US army's harassment of South Korean civilians and Seoul's initiative to take back the war-time command control from Washington, among others.